The mechanical design of all CLA reels is consistent throughout the series, but improvements have been made to the four largest sizes (4-7) to support their use in battling bigger fish. When comparing the larger CLA reels to the smaller sized 1, 1.5, 2 and 3 reels, you will find that they have a larger sized drag knob, handle and spool cap, but most importantly, they have a STRONGER DRAG SYSTEM. To ensure smooth performance with fast-running fish, the four larger sized CLA reels have also been equipped with oil-impregnated bushings for improved spool rotation. The frame and spool have been reinforced to eliminate flexing when battling heavyweights. With a wide range of sizes available, the CLA series is appropriate for any fishing application, including Spey.